1. The Field of the Invention
The present invention relates generally to exercise equipment. More specifically, embodiments of the present invention relate to exercise devices, such as stability balls, that enhance the user's exercise by destabilizing the user.
2. The Related Technology
Over the years those engaging in physical fitness exercises have used a variety of different ways to achieve their desired exercise goals. For example, individuals exercise by carrying out routines using their own weight for resistance, such as push-ups and sit-ups. To meet their exercise needs, exercisers have also used hand weights and/or devices that use a system of cables, pulleys, weights, springs, and/or resilient
Recently, however, those engaging in physical fitness activities have recognized the value of exercise devices that place the user in an unstable position. One such device is a stability ball, also known as an exercise ball or Swiss ball.
The stability ball is a large flexible ball that is used to create instability during an exercise routine. As the unstable user exercises, he or she exercises his or her core muscles to maintain balance during the exercise routine. For instance an exerciser can lie on the stability ball while exercising with hand weights. The instability of the ball requires the user to flex and exert core body muscles to maintain balance while performing the hand weight exercise. Instead of simply exercising a targeted group of muscles, the exerciser on a stability ball also uses core or stabilizing muscles, particularly those in the abdominal region. Stability balls are known to develop balance and stability by exercising the core body muscles.
One problem with stability balls, however, is that stability balls have a tendency to move or roll relative to an underlying support surface. While it is desirable for the stability ball to create instability in an exerciser, it is undesirable for the stability ball to randomly move or roll relative to the support surface. For example, a stability ball that is instable with respect to the support surface tends to roll out of position unless the user is continuously in contact with it. A user can become occupied with maintaining the position of the ball, thus detracting from the core body training experience.
A particularly advantageous solution for stabilizing a stability ball is to place a small amount of sand or other filler material in the ball. One difficulty with placing a filler material in a stability ball is that traditional valves make it difficult to inject the filler into the ball. Furthermore, valves currently in use with stability balls prevent certain grains of filler from being placed in the ball due to grain size.